The present invention refers to a shock absorber, comprising:                a tubular housing having a front end and a rear end;        a bearing assembly sealingly mounted on the front end of the tubular housing;        a piston assembly comprising a piston mounted for reciprocal sliding movement in the tubular housing, said piston defining within the tubular housing a working chamber and an accumulator chamber disposed on the rear side and on the front side of the piston, respectively, and a stem connected to the piston and extending out of the front end of the tubular housing through the bearing assembly;        a first fluid pathway and a second fluid pathway parallel disposed for connecting the working chamber to the accumulator chamber, wherein said first fluid pathway establishes permanent fluid communication between the working chamber and the accumulator chamber; and        valve means for selectively establishing fluid communication between the working chamber and the accumulator chamber.        
Shock absorbers of this type are widely available, an example of which is known from US 2006/163016 A1.